Update `events` for `pandas` v3.0 compatibility

[jarq6c]

Short and sweet update.

1. pandas v3.0 time manipulation methods will only use h (lower case) to indicate hour. This update changes all references to hour from H to h.
2. Fill methods like (fillna, ffill, bfill) will require you to explicitly indicate that you want them to infer datatypes or must be preceded by an explicit type declaration using astype. I added an astype where needed.

Closes #246

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[jarq6c]

Thanks @aaraney !